1. Field of the Invention
The present invention is related to devices for delivering an agent to the cornea of an eye and more specifically, to devices delivering an agent to the cornea of the eye where a delivery material retains the agent to be applied to the eye.
2. Description of the Prior Art
A recent development in refractive surgery is laser epithelial keratomileusis (LASEK). This so called LASEK procedure was developed by Dr. Massimo Camellin, and is essentially a modification of photorefractive keratectomy (PRK). In the LASEK procedure, a modified trephine is used to make an incision through the epithelial layer of a patient""s cornea. A cylinder is placed on the eye over the epithelial layer outside the trephine cut. Then the cylinder is filled with a loosening agent such as a dehydrated alcohol solution for a given period of time, typically 25-45 seconds. An absorbent material such as a Weck cell or other sponge is then used to absorb the loosening agent. Next, the cornea is typically irrigated with BSS. A sharp instrument is then used to peel back an epithelial flap defined by the trephine cut and which had been treated with the loosening agent. Ablation is then performed on the portion of the cornea where the epithelial layer has been removed in order to correct the patient""s vision. The removed epithelial flap is then put back into position over the ablated corneal surface.
The application of the loosening agent to the eye can be a significant source of irritation to the patient, particularly if the loosening agent leaks from the seal between the cylinder and the cornea, thus causing a burning sensation for the patient. Therefore, it would be desirable to provide a device which would significantly reduce the chance for the loosening agent to leak beyond the surgical site.
It is known in the prior art to use a dampened sponge material on the eye for blocking the surgical light from entering the eye during suturing of the wounds. This allows the cornea to stay hydrated. In addition, it is also known to use collagen shields to apply medication, typically steroids or antibiotics immediately following cataract or corneal transplant surgery. However, these corneal collagen shields are used after surgery and are not removed by the doctor, but rather dissolve in the eye naturally over a period of time.